1. Field of the Invention
The present invention relates to a leak detection system for a pressurized pipeline in order to detect a leak and transmit a signal in order to close a valve.
2. Prior Art
A wide variety of fluid control valves are employed in pipeline fluid transfer applications and in oil and gas well site applications. While the fluid control valves may be manually opened and shut, electric, pneumatic or hydraulic actuators may be utilized with the valves to automatically open and close them. Electric actuators typically include an AC electric motor, reduction gearing, travel limiting devices, and controls to switch the electric motor on or off.
Downstream from the valve, a pipeline would be connected to move pressurized fluid, such as natural gas. Many pipelines and wells operate at high pressure, such as from 2000 to 3000 pounds per square inch (psi). Depending on the conditions encountered, various pipelines and wells produce and transport sand along with the fluid. For example, during production of natural gas from a subterranean formation, a certain amount of sand is delivered to the surface and then transported through the pipelines. When a valve is partially opened, fluid exiting the valve to the pipeline is diverted from normal axial flow and is caused to move radially outward. This causes the sand to impinge against the interior of the pipeline wall. Over time, sand can erode the inside wall of the pipeline. The pipeline immediately downstream from the valve will tend to wear more than other locations because of the passage of the fluid through the valve.
Because the wells and pipelines are often in remote locations, there may not be constant visual inspection from personnel. Accordingly, a leak or rupture can continue for a time period before being discovered.
While there are various leak detection systems which have been established in the past, there remains a need for a simple leak detection system which could be used as an adjunct to and along with existing fluid control valves and their actuators.
Accordingly, it is a principal object and purpose of the present invention to provide a leak detection system which can operate with existing fluid control valves.
It is a further object and purpose of the present invention to provide a leak detection system that may be easily added to existing fluid control valves and actuators.